Without a model number this is mostly guess work.
Some power supplies have green, amber, red light system other overheat from poor ventilation and incorporate a shut off feature some laptops need to have the charging system calibrated to properly charge.
I hope its an easy fix for you but next time a model and number would go a long way to help.

__________________The fate of those who do not listen are condemned to feel.Tinbuk3

Without a model number this is mostly guess work.
Some power supplies have green, amber, red light system other overheat from poor ventilation and incorporate a shut off feature some laptops need to have the charging system calibrated to properly charge.
I hope its an easy fix for you but next time a model and number would go a long way to help.

I tried the whole pins on the power cord thing bc I think that may have something to do with it but I don't have anything small enough to tighten them if that's the issue. Model number, I'll check...

That's what I'm afraid of. So is it something that's gonna need to be done by a pro?

Yup, I've done a few windows laptops myself, but it's a bugger of a job, get quotes and decide what is cheaper, socket repair, full motherboard replacement or new laptop.....I recommend a good windows laptop.

__________________The most elementary and valuable statement in science, the beginning of wisdom, is ‘I do not know’.

Hmm, according to the information the battery life under normal charging per day is between 2.7 and 3.2 years before a replacement in needed.
I know its a 2009 model but how long have you been on that battery?
I suspect that to be the cause

__________________The fate of those who do not listen are condemned to feel.Tinbuk3